phil@unicorn.cc.wwu.edu (Phil Nelson) (11/12/90)
Hi,
I was looking over the information on the SCN2681s and how they
are configured in the pc532 and I discovered something that I
wondered if it was really true. By the documentation I have, it
looks like the following control signals are connected to the input
and output ports in the following way:
RTSA OP0
RTSB OP1
DTRA OP2
DTRB OP3
RxRDYA OP4
RxRDYB OP5
(Notice the alternating Port A on even OP and Port B on odd OP.)
And then...
CTSA IP0
CTSB IP1
** DCDB IP2
** DCDA IP3
Is it really wired that way or are the schematics wrong or are my
documents that describe the pinout for the 2681 wrong?
Thanks!
--Philgeorge@wombat.bungi.COM (George Scolaro) (11/13/90)
[In the message entitled "SCN2681 DUARTs" on Nov 11, 16:42, Phil Nelson writes:] > > Hi, > I was looking over the information on the SCN2681s and how they > are configured in the pc532 and I discovered something that I > wondered if it was really true. By the documentation I have, it > looks like the following control signals are connected to the input > and output ports in the following way: > RTSA OP0 > RTSB OP1 > DTRA OP2 > DTRB OP3 > RxRDYA OP4 > RxRDYB OP5 > > (Notice the alternating Port A on even OP and Port B on odd OP.) > And then... > CTSA IP0 > CTSB IP1 > ** DCDB IP2 > ** DCDA IP3 > > Is it really wired that way or are the schematics wrong or are my > documents that describe the pinout for the 2681 wrong? Yes this is correct. The 2681 allocates IP2 and IP3 as general purpose inputs. I just used them any old how. As Dave mentions to me, this makes it a tad harder on the software - but then he agreed with my allocation in the first place! maybe he wasn't listening to me then... Note that the schematics are 100% representative of the PCB - the netlist was used to route the board and was then back annotated (to the schematics) and checked again. best regards, -- George Scolaro george@wombat.bungi.com [37 20 51 N / 122 03 07 W]
rustyh@wam.umd.edu (Rusty Haddock) (11/14/90)
In article <9011121511.AA04945@wombat.bungi.COM> george@wombat.bungi.COM (George Scolaro) writes: >[In the message entitled "SCN2681 DUARTs" on Nov 11, 16:42, Phil Nelson writes:] I suppose you guys know about the SCC2692 which is a CMOS replacement for the SCN2681. I have used it as a drop-in replacement and it's great (cool as a cucumber). There are a few insignificant differences (outlined in ap-note AN414 from Signetics.) If you havn't seen it call Philips/Signetics (408)991-2000. Its also available in a PLCC package. -- Rusty Haddock o {uunet,att,rutgers}!mimsy.umd.edu!fe2o3!rusty Laurel, Maryland o "IBM sucks silicon!" -- PC Banana Jr, "Bloom County"